NightSkyre... I'm new to commuting (just started this week) and tried it on my "comfort bike"... a trek 100 navigator. I did the commute fine but this wasn't the most efficient machine on the bike paths that day. I talked with several people on road bikes and they told me i'd move along alot quicker on a road bike.
I too was on a budget. The bikes that I really wanted to get were in the 1300-1800 dollar range. I couldn't do it. Anyway, I turned to the "bikes" section on craigslist.com to find a good used bike. I found several good bikes but needed to find a frame that fit me. I found what I was looking for. A good aluminum frame (specialized alles elite - 2000 model), ultegra components, bontrager race wheel set, a computer, an excellent saddle and all this for $800. Anyway, this is an excellent bike and I looked up just the components as to their value - I would have had to pay $1500 for the components alone on this bike if they were new. The previous owner worked at a bike shop and meticulously maintained this bike. He wanted to buy a new carbon fiber frame for himself and that is why he was selling (I'm sure that he got a great discount on the components on his former bike.)
Anyway, if you're comfortable with used... I think that might be the way to go. You may not find what you want exactly.. but you could spend the money saved to put what you want on the bike.